1. Field of the Invention
The present invention relates to a thin film magnetic head having an inductive magnetic transducer for writing and a method of manufacturing the same.
2. Description of the Related Art
In recent years, an improvement in performance of a thin film magnetic head is demanded in accordance with an increase in areal density of a hard disk drive. As a thin film magnetic head, for example, a composite thin film magnetic head in which a recording head having an inductive magnetic transducer for writing and a reproducing head having a magnetoresistive (hereinbelow, referred to as MR) element for reading are laminated is widely used.
The recording head, for example, comprises: a top pole and a bottom pole which are disposed on the top of, and on the bottom of a write gap, respectively, while sandwiching the write gap made of a non-magnetic insulating material such as aluminum oxide (Al2O3; hereinbelow, simply called “alumina”); a coil for generating the magnetic flux which is disposed in a space between the top pole and the bottom pole; and an insulating layer for embedding the coil in the space between the top pole and the bottom pole. Each of the top pole and the bottom pole has a uniform width which is almost the same as each other in the vicinity of the write gap in a region on a side close to a recording medium facing surface (air bearing surface) facing a magnetic recording medium (hereinbelow, simply called “recording medium”), thereby a trim structure which specifies a recording track width is constructed. For example, after forming the top pole including a portion (hereinbelow, simply called “uniform width portion”) having the uniform width for defining the recording track width of the recording medium, by using the uniform width portion as a mask, the write gap and the bottom pole are etched in a self-aligned manner, and thereby the trim structure is formed.
Incidentally, in recent years, some requests for improvements are made with respect to manufacturability and performance of the thin film magnetic head. As a request from the viewpoint of manufacturability, for example, it can be provided to simplify manufacturing processes so as to shorten manufacturing time. Additionally, as a request from the viewpoint of performance, for example, it can be provided to extremely micrify the width of the trim structure (pole width) to the order of submicrons (for example, no more than about 0.5 μm) so as to increase the track density of the recording medium in order to achieve high recording density.
However, conventionally, there are problems that it is difficult to shorten the manufacturing time because a lot of manufacturing processes are necessary for manufacturing the thin film magnetic head, and that it is difficult to extremely micrify the pole width with high precision because processing accuracy is not sufficient at the time of etching the write gap layer and the bottom pole in a self-aligned manner.